Cheers guys, so from what i can tell active carbon is used just for the first few weeks it then becomes inactive and becomes a biological filter media.

I'm planning a 200l set up and will have relitivly low lighting 1-1.5wpg and will have mainly crypts and moss in with a few Echinodorus plants I'm planning on having ADA substrate with added Iron or multi bottom and would like to liquid dose K once a week with water changes. Does this sound ok? too much? too little?

Should i not dose any liquid ferts for the first few weeks if i use carbon?